Steam-boiler furnace



(No Model.)

M. A. POSTER.

STEAM BOILER FURNACE.

Patented Dec. '1, 1885 we my llurrnn STATES Parent MICHAEL A. FOSTER, OF ST. LOUIS, MISSOURI.

STEAlVi BOlLEY-i FURNACE.

forming part of Letters Patent No, 331,699, dated December 1, 1885.

Application filed February 25. 1885. Serial No. 156,979. (No model.)

To all whom, it may concern:

Beit known that I, MrcrmnL A. Fosrnn, of the city of St. Louis and State of Missouri, have invented a certain new and useful Improvement in Steam-Boiler Furnaces, of which the following is a full, clear, and exact description, reference being had to the accoinpanying drawings, forming part of this specification.

The improvement applies more especially to upright cylindrical boilers, although some or all of the features may be applied to other boiiers.

Figure 1 is a front view, with part broken away, showing parts of the interiorin section. Fig. 2 is a horizontal section at 2 2, Fig. 1. Fig. 3 is a bottom view of the boiler. Fig. 4

is a detail vertical section at 4 i, Fig. 1. Fig. 5 is an inside view of the door. Fig. 6 is an elevation of the uprightgrate. Fi 7 is a modification in elevation of the upright grate.

The boiler proper may have the usual construction found in boilers of this class,the part in proximity to the furnace having an outer shell, A, and an inner shell, B, and an annular bottom, 0.

D is the base on which the boiler and furnace-grate are supported. The furnacegrate has two concentric rings, a and e, and bars 6 between the two rings. These bars,with the rings, constitute an annularhorizontal grate, E. The bars c are shown extending radially; but this is nonessential, as the bars may be arranged in any preferred manner. The grate E has studs extending; downward for engagement with a lever, F, by which the grate may be turned or shaken. The lever F has a socket at ft'or the reception of either of the studs 6", and the end of thelever has afork, f to engage the lower end of a tube, G, which passes through the center of a crucial frame, H, forming the middle of the grate E. The lower end of the tube G has aflange or collar, upon which the forked end of the lever F is supported when in use.

9 is a collar on the tube G. which bears upon the top of the frame H. The tubeG er:- tends up vertically from the frame H, and is open from top to bottom, so that air from the ash pit I. may ascend the tube and escape from the top into the furnace-space of the boiler.

J is an upright grate composed of a circular bottom ring, j, resting in a circular rabbetgroove at e in the top of the ring e, inclined bars j, and a top ring, j connected to the ring j by the bars 3'.

K is a cap extending horizontally from the top of the grate J upon every side. This cap I prefer to make of baked fire-clay,as it is sub jected to a high temperature. Iprefer to make the cap with perforations 7c, and with notches or gaps 7; at the edge, to increase the heating surface and to] allow the ascending gases to pass through the cap. The cap K has a central neck, 7d, which fits within the ring j and rests upon a collar, 7-, upon the tube G, the tube passing centrally through the deflecting cap K. The air passing through the tube G tends to keep the tube cooler than it would otherwise be, and thus preserves it from the weakening and destructive effects of extreme heat.

L is a steanrpipe, which is fixed in the ashpit beneath the level of the grate E, as shown, the steannpipe having jet holes upon its inner side, so as to send steam-jets beneath the fire to enter the fire and assist combustion. The live steam from the boiler is fed to the steampipe L through a pipe, M, supplied with a Valve, m.

is a pipe through which the products of combustion may be in part returned to the ashpit to complete thecombustion of the same. No claim is, however, made herein to this device for the return of products of combustion.

O is the orifice through which fuel is fed to the fire.

P is the fire-door, which has a front plate, p, with an orifice at p to allow the passage of atmospheric air into the furnace. The door has a hota-ir chamber, p with top plate, 11 and side plates, 1)". A part of the bottom of the chamber p and of the inner wall thereof is formed of fixed walls at 12 The air-chamber p has at the inner side a discharge-mouth, 1), formed by the top plate, 29 and side plates, p, and a movable jaw, Q, which may be raised or lowered to regulate the aperture of the mouth. The jaw turns or works on pivots at R, and has an arm, S, extending outward through the aperture 22. The weight of the Q tends to keep it'open, so that all that is needed is to provide a device to hold down the arm S in the required position to regulate the aperture of the mouth to the desired size to admit a proper amount of atmospheric air through it. The inner walls of the air chamber or passage 19 and the walls and jaw of the mouth p become much heated, and so raise the temperature of the air passing through them to a high degree. To increase this heating action, the top plate, 19 and the jaw Qhave studs q extending into the mouth, which become heated by connection with the plates and impart their heat to the air passing by them. The edge of the jaw has serrations q, to check and break up in some degree the current of entering air.

The device I have shown for holding down the arm S consists of a cam, T, turning on a pivot, t, and having a curved form, so that by moving it upon its pivot it has the described action upon the arm.

It will be observed that the form of the door is such that it cannot be swung upon hinges at one edge, as usual. I support the door on a crane, U, which is supported upon hinges V. The free end of the crane has hinge-links l/V,jointed at one end to the crane and at the other end to the door. The arrangement is such thatthe door may be swung out on a horizontal plane, and may be inserted and removed into and out of the orifice O by straight inward and outward movements.

It will be understood that the horizontal grate E may be turned in its bearings, and that the upright grate J may be turned on the horizontal one. Thus the two grates may be both shaken at the same time, or the grate J may be shaken singly, or may be turned to bring another side to the front.

In the modification shown in Fig. 7 the tube G and cap K are dispensed with. It

There is an annular body of burning material which is presented to the action of the air passing horizontally through the door, so that the upright grate and the perforate door with heating-chamber act conj ointfor controlling the position of said arm, as

set forth.

2. In a furnace-door, the combination of a hot-air space, an aperture in the outer plate of the door for the admission of air thereto, and a movable jaw on the inside for regulating the passage of air therethrough, as set forth.

3. The combination, in a furnace door, of a mouth discharging atmospheric air into the furnace, and studs extending from the top, bottom, or sides of the mouth into the air-current.

4. The combination, in a furnacedoor, of an air chamber or passage, a mouth extending from said chamber or passage into the firespace, having a fixed jaw and a movable jaw, and studs extending from the jaws into the air-current passing through the mouth.

5. The combination,in a furnace door,of an air chamber or passage in communication with the outer air, and having a mouth discharging within the furnace, and having a movablejaw with an arm extending to the outer side ofthe door,for the purpose set forth.

MICHAEL A. FOSTER.

In presence of GEO. H. KNIGHT, SAML. KNIGHT. 

